Trigger points, also known as myofascial trigger points, are areas of hyperirritability in the soft tissue structure. These can be acute sources of pain or latent, unnoticed by the client until pressure is applied by the practitioner.
Trigger points are manifested as small contraction knots in the muscles, that control the state of contraction and active ones may cause muscle spasm and referred pain.
This is great for / symptom indicators:
SPain and body aches